Bos R R, Rozema F R, Boering G, Nijenhuis A J, Pennings A J, Verwey A B, Nieuwenhuis P, Jansen H W
Department of Oral and Maxillofacial Surgery, University of Groningen, The Netherlands.
Biomaterials. 1991 Jan;12(1):32-6. doi: 10.1016/0142-9612(91)90128-w.
Samples of high-molecular-weight poly(L-lactide) (PLLA) (Mv = 9.0 x 10(5), a biomaterial developed for plates and screws used in internal fixation of jaw fractures, were implanted subcutaneously in the backs of rats to study tissue reaction to PLLA and to follow the degradation process. The PLLA seemed to follow the degradation pattern typical of biodegradable polyesters. After pure hydrolysis up to about 104 wk, phagocytic activity of macrophages was found at about 143 wk. Full resorption of PLLA was not demonstrated in this study. Except for the early and final parts of the implant period, no acute or chronic inflammatory reaction was observed. No implant was rejected. It is estimated that more than 3 yr will be required for total resorption of PLLA. For bone-healing this long period is of no practical importance. There is no need for removal of PLLA after fracture healing as is the case with metal fixation devices. Thus, PLLA has potential application in internal fixation of fractures and osteotomies in the maxillofacial region and other fractures that are not too heavily loaded in the human body.
高分子量聚（L-丙交酯）（PLLA）（重均分子量Mv = 9.0×10⁵，一种用于颌骨骨折内固定的钢板和螺钉的生物材料）样本被皮下植入大鼠背部，以研究组织对PLLA的反应并跟踪降解过程。PLLA似乎遵循可生物降解聚酯的典型降解模式。在大约104周的纯水解后，在大约143周时发现巨噬细胞的吞噬活性。本研究中未证明PLLA完全吸收。除植入期的早期和末期外，未观察到急性或慢性炎症反应。没有植入物被排斥。据估计，PLLA完全吸收需要超过3年时间。对于骨愈合而言，如此长的时间没有实际意义。与金属固定装置不同，骨折愈合后无需取出PLLA。因此，PLLA在颌面部区域骨折和截骨以及人体中负荷不太重的其他骨折的内固定方面具有潜在应用价值。
